Tappet



y 14, 1953 M. L. THOMPSON 3,089,472

I TAPPET Fild Oct. 9, 1961 INVENTOR Mme/01v LEE 7 /044, 50

ii 1 42% d/m/ 3,889,472 TAPPET Marion Lea Thompson, 2734 Eastvale,Rolling Hills, Calif. Fiicd Get. 9, 1961, Ser. No. 143,918 9 Claims.(Cl. 123-98) This invention relates to tappets or valve lifters forinternal combustion engines, and more particularly to tappets which maybe rapidly yet firmly installed in an engine or motor housing and easilyremoved therefrom, and it also relates to the employment of a novel toolto rapidly and accurately align the tappets with respect to an enginecam shaft and other tappets to achieve proper timing, so as toaccomplish efficient engine operation.

A major object of this invention is to provide a tappet employed as avalve lifter for internal combustion engines which may be rapidly andfirmly installed into an engine housing and which may be readily removedfrom the installation.

Another object of this invention is to provide a tappet of the characterdescribed wherein the tappet, with the assistance of a tool, may beaccurately aligned with respect to an engine cam shaft and other tappetsto achieve an accurate timing to effect efficient engine operation.

A more specific object of this invention is to provide a tappet of thecharacter described which includes a body having a taper therein, thetaper being encircled by a compressible ring that may be inserted into abore adapted to receive said tappet, whereby the taper and ring serve toachieve a positive and firm installation of said tappet in the enginehousing, but which further serve to provide ready removal of the tappetfrom its installed position.

Another more specific object of this invention is to provide a tappet ofthe character described wherein the body of the tappet includes opposedflats adapted to receive a tool to align the tappet with respect to theengine cam shaft and other tappets so as to achieve the lifting ofvalves at the proper time and in the proper sequence.

Further objects and advantages of this invention will appear in thefollowing specification, wherein the details of construction and mode ofoperation of a preferred embodiment of the device of the presentinvention are described with reference to the accompanying drawings, inwhich:

FIG. 1 is a vertical cross-sectional view illustrating a pair of tappetsinstalled in an engine housing and associated with an engine cam shaft;

FIG. 2 is a cross-sectional view taken on line 22 of FIG. 1, and showingan aligning tool installed on a pair of tappets for aligning the samewith the engine cam shaft and each other;

FIG. 3 is a plan view taken on line 3-3 of FIG. 2; and

FIG. 4 is an exploded, fragmentary perspective view illustrating thetaper in the body of a tappet and the split ring associated therewith,together with a flat on the body adapted to receive an aligning tool.

Referring to the drawings, and initially, particularly to FIG. 1, enginehousing 10, having a plurality of fluid passages and ports 12 and 14therein, also has a plurality of bores 16 adapted to receive tappets 18.Extending through engine housing is a cam shaft 20 on which are aplurality of cams 22 each of which engage an associated tappet 18 toactuate the same to lift a valve stem 24 of a valve.

The tappets 18 each include a hollow, generally cylindrical body 26which encircles an elongated cylindrical and reciprocal plunger 28, oneend of which is bi- 3,089,472 Patented May 14, 1963 furcated andsupports a rotatable roller cam follower 30 engageable by a cam 22. Thecylindrical body 26 includes a skirt portion 32 which has a pair ofopposed slots 33 therein that receive the cam follower 30 as theactuating cam 22 on cam shaft 20 forces the rise of the roller 30 fromthe position illustrated on the left in FIGURE 2 to the positionillustrated on the right in said FIGURE 2. Spaced from the skirt portion32 and integral with the cylindrical body 26 is an annular collar 34.The uppermost end 36 of body 26 is externally threaded to receive aninternally-threaded nut 38, and between end 36 and collar 34, the body26 has a tapered surface portion 40. The narrowest portion of taper 40occurs adjacent threaded end 36, and taper 40 flares outwardly towardcollar 34, as may best be seen in FIG. 4.

A split cylindrical sleeve 58 :having an annular flanged end 52 ismounted on taper 4t Said sleeve 50 has a substantially uniform internaldiameter and a substantially uniform external diameter.

Initially, each tappet 18 is gently inserted into a bore 16. To achievean alignment of the tappets, the threaded portion 36 of each tappet hasa pair of parallel opposed flats 42 thereon that are in linear alignmentwith slots 3.3. Flats 42 mate with corresponding flat portions 44 formedin generally oval-shaped openings 46 of an alignment tool 48. Whenalignment tool 48 is mounted on tappets 18 in the manner illustrated inFIG- URES 2 and 3, the flats 44 of tool 48 are generally in abuttingrelationship with flats 42, and such relationship assures substantiallyexact alignment of a pair of adjoining tappets with respect to eachother.

Alignment tool 48 may incorporate two or more openings 46 therein andpreferably two. While mounting of alignment tool 48 on a pair ofadjoining tappets 18, camshaft 24 is manually rotated to achieve properinsertion of the tappet 18 in bore 16, which is accomplished by thelifting of roller 30 by cam 22. It is to be understood that in lieu of aseparate alignment tool 48, a permanent holding fixture having openings46 therein may comprise a permanent installation on the engine housing10.

When a pair of tappets 18 are substantially exactly aligned with respectto each other and cam 22, nut 38 is tightened against flange 52 ofsleeve 50. As the sleeve 50 is thus forced downwardly on taper 40 intobore =16 by nut 38, taper 40 will expand sleeve 50, such expansion beingresisted by the wall of bore 16. In this manner tappet 18 is firmlysecured in bore 16. Flange 52 provides a stop that limits the insertionof sleeve 50 into bore 16.

To remove tappet 18 from the bore 16, it is merely necessary to back offon nut 38 and lightly tap tappet 18, thus breaking the seating seal ofsleeve 50 in bore 16.

Removably supported on the upper end of the cylindrical plunger 28 is acircular pad 54 which includes a projection 56, in turn received in theuppermost end of plunger 28. Pad 54 has a depression therein adapted toreceive valve stem 24. Seated against pad 54 for the purpose of forcingcam follower 30 to follow cam 22 is a compression spring 58.

While the inst-ant invention has been shown and described herein, inwhat is conceived to be the most practical and preferred embodiment, itis recognized that departures may be made therefrom within the scope ofthe invention which is therefore not to be limited to the detailsdisclosed herein, but is to be accorded the full scope of the claims.

I claim:

1. A tappet for internal combustion engines comprising: a hollowcylindrical body receivable in a bore to receive a reciprocalcylindrical plunger having a roller cam follower thereon engageable witha cam on a rotatable camshaft, said body having an external taperedportion thereon; a first means encircling a portion of said taperedportion for releasably securing said tappet in the bore; and a secondmeans on said tappet receivable by alignment means for aligning saidtappet in said bore with respect to adjoining tappets and with respectto the cam on the camshaft.

2. A tappet according to claim 1, wherein said first means includes asplit cylindrical sleeve having a uniform internal and a uniformexternal diameter.

3. A tappet according to claim 2, wherein said split cylindrical sleeveincludes an annular flange disposed so as to limit the urging of saidsleeve into said bore.

4. A tappet according to claim 1, wherein said first means includes acompressible and expandable sleeve.

5. A tappet according to claim 1, wherein said second means includesflats.

6. A tappet according to claim 1, wherein said second means includes apair of opposed parallel flats receivable by alignment means havingcorresponding fiats.

7. A tappet for internal combustion engines comprising: a hollow,cylindrical body receivable in a bore to receive a reciprocalcylindrical plunger having a roller cam follower thereon engageable witha cam on a rotatable camshaft, said body having an external taperedportion thereon, and having a pair of opposed slots therein to receivethe roller cam follower when the plunger is lifted by the action of thecam; a split, cylindrical sleeve encircling a portion of said taperedportion, said sleeve having a substantially uniform internal and asubstantially uniform external diameter; a first means on said body forurging said sleeve into said bore to achieve expansion of said sleeve bysaid tapered portion, said expansion being resisted by the wall of saidbore to secure said tappet in said bore; and a second means on said bodyin linear alignment with said slots to receive an aligning tool foraligning said tappet in said bore with respect to adjoining tappets andwith respect to the cam on the camshaft.

8. A tappet according to claim 7, wherein said second means includes apair of opposed parallel flats.

9. A tappet for internal combustion engines comprising: a hollow,cylindrical body receivable in a bore to receive a reciprocalcylindrical plunger having a roller cam follower thereon engageable witha cam on a rotatable cam shaft, said body having an externally taperedportion thereon, and having a pair of opposed slots therein to receivethe roller cam follower when the plunger is lifted by the action of thecam; a split, cylindrical sleeve encircling a portion of said taperedportion, said sleeve having a substantially uniform internal and asubstantially uniform external diameter; a first means on said body forurging said sleeve into said bore to achieve expansion of said sleeve bysaid tapered portion, said expansion being resisted by the wall of saidbore to secure said tappet in said bore; and a pair of opposed parallelflats on said body to align in parallel and generally abuttingrelationship with a mating pair of opposed parallel flats in an openingin an aligning tool.

References Cited in the file of this patent UNITED STATES PATENTS

7. A TAPPET FOR INTERNAL COMBUSTION ENGINES COMPRISINT: A HOLLOW,CYLINDRICAL BODY RECEIVABLE IN A BORE TO RECEIVE A RECIPROCALCYLINDRICAL PLUNGER HAVING A ROLLER CAM FOLLOWER THEREON ENGAGEABLE WITHA CAM ON A ROTATABLE CAMSHAFT, SAID BODY HAVING AN EXTERNAL TAPEREDPORTION THEREON, AND HAVING A PAIR OF OPPOSED SHOTS THEREIN TO RECEIVETHE ROLLER CAM FOLLOWER WHEN THE PLUNGER IS LIFTED BY THE ACTION OF THECAM; A SPLIT, CYLINDRICAL SLEEVE ENCIRCLING A PORTION OF SAID TAPEREDPORTION, SAID SLEEVE HAVING A SUBSTANTIALLY UNIFORM INTERNAL AND ASUBSTANTIALLY UNIFORM EXTERNAL DIAMETER; A FIRST MEANS ON SAID BODY FORURGING SAID SLEEVE INTO SAID BORE TO ACHIEVE EXPANSION OF SAID SLEEVE BYSAID TAPERED POR TION, SAID EXPANSION BEING RESISTED BY THE WALL OF SAIDBORE TO SECURE SAID TAPPET IN SAID; BORE; AND A SECOND MEANS ON SAIDBODY IN LINEAR ALIGNMENT WITH SAID SLOTS TO RECEIVE AN ALIGNING TOOL FORALIGNING SAID TAPPET IN SAID BORE WITH RESPECT TO ADJOINING TAPPETS ANDWITH RESPECT TO THE CAM ON THE CAMSHAFT.